Safety lock for counterbalancing devices



Sept. 25, 1928.

C. P. GRlMEs SAFETY LO CK FOR COUNTERBALANCING DEVICES Filed Jan. 6, 1927 ATTORNEYS,

Patented Sept. '25, 1928.

UNITED STATES PATENT OFFlCE.

CHARLES 1'. (minus, or SYRACUSE, NEW YORK, ASSIGNOR T PEDWYN BALANCER coaromrron, or SYRACUSE, EW YORK, A conrona'rron 01 NEW onx SAFETY LOCK FOB COUNTERBALANCING DEVICES.-

Application fil ed January This invention relates to winding drums which are actuated in one direction by a spring and has for its object a particularly simple and efficient safety lock for locking the drum from turning movement under the influence of the weight or load on the'cable winding on the drum, if the drum spring breaks.

The invention consists in the novel tea- 1 tures and 'in the combinations and construction's hereinafter'set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

V Figure 2 is a side elevation of a counterbalancing device embodying my invention.

Figure 1 is a sectional view on line 22, Figure 2.

I have here shown my invention as embodied-in a counterbalancing device or a device used for counter-balancing tools such as electric drills and the like although it is equally applicable in any machine having a spring wound drum regardless of the character of the load carried by the ing on the drum.

The illustrated embodiment of my invention 'comprises,rgenerally, a spring wound drum and a spring for winding the drum, a lock normally in ineffective position and having means for moving it into effective position to lock the drum from turning it the spring breaks and means for normally holding the lock in ineffective position, said means beingconnected to the drum spring and held thereby under the tension of the drum spring in its normal position where it holds the lock in ineffective position, all wherebyif the drum spring breaks, the lock is free to move into engagement with the drum and hold it from turning.

1 designates the drum whichis here shown as mounted upon aspindle 2 to rotate about the same, the spindle being mounted in a suitable support as a casing 3.

H 4 is the drum spring coiled about the axis of the spindle 2 and connected at its outer end cable wind- 6, 1927. Serial No. 159,284.

to the drum and at its inner end to a spring abutment 5 also mounted on the spindle 2 to rotate relatively thereto and also rotatable in a central'bearing 6 in a detachable outer wall 7 of the casing, the abutment extending to the outside of the casing'in order tobc turned to tension the spring.

8 is the load supporting cable winding on the drum. v

The casing 3 is provided with means on the upper side thereof for connection to an" overhead support, this means being here shown as a lug 9 and link 10 pivoted to the lug. The'cable 8 extends out through a taned on the spindle 2 and the free end of the spindle is supported in this abutment as the abutment is supported in the bearing 6. The outer end of the spring is secured to 8. lug 12 within the drum. 7

The lock is normally held from moving into locking position by the tension of the spring 4 acting through a detent coacting with the lock. The lock is here shown as a spring pressed bolt or rod 13 carried within the casing 9 by the removable cover plate 7 thereof and being here shown as slidable in lugs 15, 16 on the inner side of said cover plate 7 and as movable vertically so thatits lower end projects into notches in the drum orinto spaces between lugs 17 on the front side of the drum. The bolt or rod 13 is spring pressed by a spring 18 interposed bethe hub of the rock arm 19 mounted on the rod. The bolt is held in its retracted position against theaetion of the spring 18 by a detent rotatable with the spring abutment, this detent being here shown as any oneof a tween the lug 16 and a suitable shoulder on v ,7 plurality of teeth provided on flange 21 and coacting with the rock arm 19 which exthe spring.

the eight oriload on the-cable- 8. Hence,%the

' the drunrfrom turning and means actuated rotate ab'o1;1t the 5 same, ;a spring abutment position assumed -W-h en the with 1 its. detent 20.

l 1 tends out through an opening 23 in the Wall 7. The abutment 5 is also provided With a Wrench hold 24 at its extreme outer end'by means of which it can-be turned to tension The rock arm 19 'serveslto hold the abutment from retrograde movement,

that is, to hold the spring from untensioning. v The spring :18 is anchored at'its ends tothe' lug 16 and the rock arm 1-9011 thehub thereof so that the springalsoiacts asa torsion spring to rock the shaft orbo'lt in'one direction or the other. Preferably it rocks :the shaft in such direction to move the arm 19 toward its arm isyengaged Tl heremovable cover plate 7 is; eld in- 13?- si tio nsby suitable screws 25 and also it 1s formed vwith av suitable Qpen ng 28 nonmallly closed by i-a. cover 29 held ,in position by screws 3().- v e ;Du-ring the tens'ioning of thes;prin-g,fthe rockarm 19 is swung laterally outwardly outlofiengagement with the teeth 20 and when theispring is tensioned, it is -,ag'a in' sivunglatoral-1y inwardly in-to engagement with the teeth. The rock arm is fkeyed :totheboltor rod 13 ts o .-that-the bolt orrod-alsoroclrs durng his operation. v i

In operation, after the spring has been: tensioned', the parts are in their: positions shown in -F-igure 2. gIf, however, the drunisspri-ng breaks, the holding force on the locking bolt 13({13 relnQ-vethso that 1the sp1fi1ng 18 is free to react and force the bolt into engagement with a the drum orbet-ween thelugs 'LT and thus hold,

the drinn from turning under-the influence of liability of injuring workmen by the falling oi the load on the cable'if t-he spring breaks islentirely ielin inated.

ellihatl. claim 1S 1. In a device oft-he class describedpthe combination of a windin drunna spring acting on. the driun to -W ing. normally in T ineffective position, ineanj tending to move it in Qfi'QCilXGyPOSlflEIQll to lock bythe spring normally holding the "lock out kot'cfiiective position"whereby if the spring brea is 'the lock moves into effect-lye position. I 2. 3h device of the -,cl.ass described compris- 7 ing a winding .drum,a spring on the drum to 'WlIlGl 1ta snm Jressedlocl; for

holding the drum "fitomturningmovement,

tent being oonncoted. tor'the dnum. springtobe actuated thereby. Q v

413. A device of the class described, comprise rotate about t e same, ,a s p ngnbutmen ,r

it and it look for holding the drum from-turning,fthe lock :bc-

spring tending to-rmove it into looking position and means connected to the spring abutm nt an c act ngth 'tiheflofikl lw its normal position, all vvh'ereby' ifthe coiled spring ,breaks,,,the;locl is free to move into lOClilIig engagement with the drum.

i. A idQViQGsQQEIlld-QLQSS described comprising a support, an axle mounted in the support, :1- 111 cling d um m u ed on the i1 tatably gillolliltfidafil'l i the-axle, a eoilegl spirijlg connected a its inner end to-t e-splzing mentand at its outer end; to the d um, a; look arried by the suppo an mo a le int gagement evithth hum :th ld m ovement,'t-he lock being normally in opera ive po tion; sprlng e ding to mor it into locking posit-ion endidetent means connested to h spring abutmen and (me ting withthe loek to holditiii-it "normal position, all wher y i h c il b eaks,- th l ck i e o n veia 1 f= w ing engagem n with t-he drum, the lockvhaviaig a' movement into. and ou of-engagem nt w th t e ;.1 t n means to permit turn ng of the abutment: to

tensionuthe sprin o a 5. A device of the class describedcomp-rising aavinding drum, a spring sat n on h drum to Wind "it, ;a -;.s;pri-njg.; pressed ook for holding the drum from tu rning movement, V

the lock being normally in i-inefieotiive position,a-nd an' abut nent for one end of the spring, a de' tent coasting with the flock connected; to said spr ng abutment and coast ,ing With the-lock to hold the look ,in-itsinet fectivegposition, (the look also nor iatly hold ing the detent and tl nient by thegdrumir out of engagement iv-it Winding-of the spring. r y r 6. 1X "c-ount'enbalancing Fdevioe comprising pp rt,aspi dle D U.I1t ;i ;h support, a winding drum :anounted on he spindle {to he jdetent to-permit mounted on the spindle avithin the drum, a

coiled'; spri-n;g {fixed atits iouteri-end to ,the.

. biit u i on more 7 and -Fbe1n;g=- n ouable tension the spring, a {lock carried; bygtl'ie support and movable into engagement with the drum to hold -it fro1-n.- nning, a springt mmally pressingthe lock nto-eflective position, a detent rota-table "with;thejspring abutment and coacting WithrtellQlQCk to holdthe lock in its reti-acted position.

counterbalancing device comprising a support, a spindle mounted in the support, a

Winding drum mounted on the spindle to ro-,

tate about the same, a spring abutment mounted on the, spindleWithin the. drum, a coiled spring fixed at its outer end to the drum and at its inner end to the abutment, the abutment being rotatable about thespindle to tension the spring, a lock carried by the support and movable into engagement with the drum to hold it from turning, a spring normally pressing the look into effective position, a detent rotatable With the spring abutment and co acting with the lock to hold the lock in its retracted position, the portion of the lock coacting with the detent'being shiftable out of the path of the detent to permit turning of the abutment to tension the spring.

'8. A'device of the class described comprising a support, a spindle mounted in the support, a Windinr drum mounted on the spindle'to rotate about the same, a spring abutment rotatable about the spindle. a coiled spring connected at its outer end to the drum and at its inner end to the abutment, a lock comprising a bolt carried by the support at one side of the drum, a spring acting on the bolt to press it into engagement with the drum to hold the drum from turning, a detent mounted on the springabntment, a rock arm mounted on the bolt and coacting with the detent, the detent holding the bolt in its retracted position.

9. A device of the class described comprising a support, a spindle mounted in the support, a winding drum mounted on the spindle to rotate about the same, a spring abutment rotatable about the spindle, a coiled spring connected at its outer end to the drum and at its inner end to the abutment, a lock comprising a bolt carried by the support at one side of the drum, a spring acting on the bolt to press it into engagement with the drum to h old the drum from turning, a detent mounted on the spring abutment, a rock arm mounted on thc'bolt and wanting with the detent, the detent. holding the rod in its retracted position, the rock arm being movable laterally out of engagement with the detent to permit turning of the spring abutment to tension the spring. 7 v

10. A counter-balancing device comprising a casing, adrum mounted in the casing, a

a load carrying cable Winding on the drum, a

spring mounted in the casing and connected to the drum to turn it to Wind the cable thereon, a lock in the'casing normally out of opera-V l 11. In adevice of the class described, the combinationiof a Winding drum, a spring 00- aetingon the drum to wind it, a spring pressed lock for holding the drum from turning, the lock being normally. in ineflecti-ve position, and means operated by the coil spring to hold the lock from actuation by its spring.

12. In a device of the class described, the combination of a Winding drum, a spring coacting on the drum to Wind it, a spring pressed lock for holding the drum from turning, the lock being normally in inefi'ective position, and means operated by the coiled spring to hold the look from actuation by its spring, the lock including a portion shift-able out of engagement with said means to permit Winding of the coiled spring.

13. A counterbalancina device comprising a casing open at one side, and a removable cover for the open side, a drum mounted in the casing, a load carrying cable winding on the drum, a coiled spring mounted in the casing and connected to the drum to turn it to Wind the cable thereon, a lock normally,

out ot operative position and movable into position to lock the drum from turning under the influence of the load, the lock having means for moving it into effective position, and means controlled by the coiled spring to normally hold the lock from movement into operative position, said lock being carried by the cover.

14. A counterbalancing device comprising a casing ooen at one side, and a removable cover for the open side, a drum mounted in the casing, a load carrying cable winding on the drum, a coiled spring mounted in the loo casing; and connected to the drum to turn it 7 to wind the cable thereon, a lock normally out of operative position and movable into position to lock the drum from turning under the influence of the load, the lockhaving means for moving it into efiective position, means controlled by the coiled spring to normally hold the lock from movement into operative position, said lock being carried by the cover, the'lock holding means having a portion located outside of the cover and the lock including a portion extending through the cover to the outside thereof coacting with said holding means. 7

' 15. A counterbalancing device comprising va casing open at one side, and a removable cover for the open side, a. drum mounted in the casing, a load carrying cable winding on the drum, a coiled spring mounted in the casing and connected to the drum to turn it to wind the cable thereon, a lock normally out of operative position and movable into position to lock the drum from turning under the influence of the load, the lock having means for movin! it into effective position, means controlled by the coiled spring to normally hold the lock from movement into operwith tlw H lding means to pefirifit windin of the spring: I V

In tst-i mdfly whergo'f; I1 have herelnifio 10 signet'l my-name, a t Syla'us", in the oufxty' ofa@nonda a,-: in the Skate of New York, thisalst dayof December,- 1926, r r 

